Kentucky Bluegrass
Poa pratensis · Cool-season, Perennial, C3 grass
Grass Family
Poaceae, Subfamily Pooideae, Tribe Poeae
Grass Category
Lawn/Turf, Sports Turf, Golf Course (Fairways/Roughs)
Variety / Cultivar
Common or Elite Cultivar (e.g., 'Midnight', 'Mazama', or 'Kenblue')
Hardiness Zones
USDA Hardiness Zones 2-7; excellent cold tolerance; poor performance in high heat/humidity (Zone 8 and above) where it lacks durability.
About This Grass
A dense, fine to medium-textured grass with a characteristic deep blue-green color. It forms a uniform canopy and produces small, pyramid-shaped panicle seed heads if left unmowed.
Blade Characteristics
Blade width: 2-4mm (medium-fine); Shape: V-shaped or flat; Tip: Distinctive boat-shaped (keeled) tip; Vernation: Folded in the bud; Ligule: Short, membranous, and truncated; Auricles: Absent; Color: Deep emerald to blue-green.
Root System
Moderately shallow fibrous roots supported by extensive rhizomes; forms heavy thatch; excellent sod-forming ability and wear recovery but slow to establish from seed.
Growing Information
Origin Region
Native to Europe, Northern Asia, and the mountains of Morocco; widely adapted to temperate climates globally
Growth Habit
Rhizomatous (spreading via underground stems), form a dense, tight-knit sod mat
Sunlight & Water Needs
Full Sun preferred (6-8 hours); moderate shade tolerance in some cultivars; high water needs (1-1.5 inches per week); enters dormancy during extreme drought.
Mowing & Maintenance
Ideal height: 2.0 to 3.5 inches; Frequency: Weekly; Fertilization: 2-4 lbs Nitrogen per 1000 sq ft annually; high maintenance level requiring periodic dethatching and aeration.
Special Characteristics
Excellent self-repairing ability via rhizomes; high wear tolerance; susceptible to Pythium blight and Summer Patch; prone to Necrotic Ring Spot; excellent winter color retention in cool climates.
Ecological Information
Introduced in North America (naturalized); provides nesting cover for ground-dwelling birds; excellent for erosion control on slopes; often blended with Perennial Ryegrass or Fine Fescue for improved diversity.